% Compare different loopy belief propagation algorithms on a graph with a single loop.% LBP should give exact results if it converges.seed = 0;rand('state', seed);randn('state', seed);N = 2;dag = zeros(N,N);dag(1,2)=1;ns = ones(1,N); bnet = mk_bnet(dag, ns, 'discrete', []);for i=1:N  %bnet.CPD{i} = gaussian_CPD(bnet, i, 'mean', 0);  bnet.CPD{i} = gaussian_CPD(bnet, i);endengines = {};engines{end+1} = jtree_inf_engine(bnet);engines{end+1} = pearl_inf_engine(bnet, 'protocol', 'tree');[time, engines] = cmp_inference_static(bnet, engines, 'maximize', 0, 'exact', 1:2, 'observed', [2], ...				   'check_ll', 0, 'singletons_only', 1, 'check_converged', []);